In conventional television apparatus, the connector for the picture tube is soldered on a printed circuit board. This circuit board includes further constituent parts such for example as potentiometers for the adjustment of the focussing voltage for the picture tube or for grey balance. These potentiometers are connected by means of printed conductors with the junction points for the picture tube connector. in addition, the focussing voltage, which is applied to a grid of the picture tube by way of the tube connector amounts for example to around 8 KV. This relatively high voltage cannot be applied without precaution by means of a printed conductor of the circuit board, because arcing and with it leakage would occur. Therefore, and for the application of the focussing voltage, special provisions are needed, for example a separate insulated wire. This wire must be soldered on the one hand to a connector of the potentiometer and on the other hand to the corresponding contact of the connector. This solution requires therefore additional applications of solder which cannot be made in the dip soldering process. In addition, such applications of solder are undesirable in the vicinity of high voltage, because the unavoidable flux vapour can have a disadvantageous effect on the degree of join. To this is added the fact that the making of the solder connections requires additional manual or machine operations.
The potentiometer for the focussing voltage must be provided with a housing consisting of high quality insulating material which guarantees for the high voltage an adequate protection against touch. In addition a high quality insulator is also necessary for the tube connector which insulator guarantees on the one hand good thermal stability and on the other hand adequate insulation of the individual contacts one to another.